Channel Nine tell us that Ryan Harris bowls “a heavy ball”. For once, they’re not wrong. Who knows exactly what a “heavy ball” is, but Harris sure as hell bowls one. There have been other exponents of one of commentary’s favourite cliches – Andrew Flintoff springs to mind – but Harris is the art’s current champion. While the run-up of a lithe thoroughbred like Mitchell Johnson flows, Harris pounds in like a bullock, reaching terminal velocity as he hurls the ball down with an action that looks so laboured it deserves to be accompanied by a tennis player’s grunt. Harris makes bowling look a painful process which, for him, it is. Amid myriad injuries, he’s somehow managed 23 Tests, including 11 on the bounce now. His record, 96 wickets at 23.2, is a triumph of perseverance, passion and graft.

Now though, all those “heavy balls” have taken a heavy toll on his fragile body. From day one, his body has been managed on a Test-by-Test basis as he’s nursed swelling at the end of each day’s play and pain getting from bed to his morning shower. The end has looked nigh a number of times but he’s been propped up by his remarkable determination. Harris and Australia’s stated aim is to prolong his Test career until the 2015 Ashes but now we might finally be staring that final match in the face.

After the third Test against South Africa, Harris will finally have an operation to remove fragments of floating bone from his near cartilage-less right knee. He’s been putting this off for months and said in January, when revealing he’d turned down the opportunity to forego the Melbourne and Sydney Ashes Tests to have the op, that his condition is no worse than it was six months ago. While this is a straightforward procedure, it is difficult to know quite how Harris will react and recover.

Saturday’s third Test will be Australia’s 18th in 53 weeks. The quirks of cricket’s schedule mean that they now won’t play another until October, when they take on Pakistan in the UAE. This presents a double-edged sword for Harris, who will be 35 by then. On the one hand, he has plenty of time to recover. On the other, the impetus that has surely carried that creaking body through these 11 consecutive matches will be broken. Harris will play little, if any, cricket to prove and achieve the fitness required for the Pakistan Tests. If he’s to return, Australia, who’ve managed Harris’s condition brilliantly thus far, will have to outdo themselves. That said, the location of those Tests may lead the management to break up Australia’s all out pace battery on pitches that don’t aid the art. Absence from the UAE would surely spell the end of Harris’s international career.

Coincidentally and not critically, Harris is enduring, by his own high standards, a lean series. He’s bowled better than his three wickets at 74 suggest but has looked jaded and even more laboured than usual and went nine spells without taking a wicket in Port Elizabeth. That a pair of matches that yield two and one wicket apiece is the worst sequence in his Test career tells of the brilliance of the rest, not the poverty of those two.

Never do press box narratives run as wild as during an Ashes series. This time there was the one about Johnson the saviour, the one about Michael Clarke’s Midas touch and the one about Australia’s new generation. Yet, as Geoff Lemon pointed out after the Perth Test this isn’t a new generation at all. There are plenty of old stagers in there and Harris’s fitness issues may well make him the first domino to fall, followed, surely, by Messrs Rogers and Haddin. That said, with the likes of Pattinson, Bird, Starc and Cummins lurking, although none are yet in Harris’s class, a fast bowler is the one commodity Australia could afford to lose.

If 24 Tests is all Harris’s body can manage, we can take comfort knowing that he lasted longer than this century’s other two fast, fearsome but fragile swingers, Shane Bond and Simon Jones. All three have shown just a glimpse of what their potential promised. We should be equally grateful that any of Harris’s potential has been realised: his blossoming came so late that he was nearly the one who got away altogether.